This invention relates particularly to seals in which a shackle of loop captured securely within a housing to close and lock the loop. Once the seal has been locked, it cannot be opened except by so breaking or deforming it or to render it incapable of being re-used.
The common seen padlock seals are often constructed by: a lead housing engaged with a soft steel wire, an aluminum sheet engaged with a terminal ball, an iron plate engaged with steel wire hook, and some even engaged with paper sheets.
Owing to their weak structure, it has been found possible to pull the shackle (the soft steel wire, the aluminum sheet and the steel wire hook) from its mate housing (the lead housing, the terminal ball and the iron plate) because when a substantial pull is applied to the shackle, the shackle bent within the housing and lose its locking effectiveness. When a shackle has been pulled from the housing, an interloper may reapply the seal or lock by reshaping and reinserting the ends of the shackle, or he may use a new piece of wire, something quite easily obtained.